/*
Language: D
Author: Aleksandar Ruzicic <aleksandar@ruzicic.info>
Description: D is a language with C-like syntax and static typing. It pragmatically combines efficiency, control, and modeling power, with safety and programmer productivity.
Version: 1.0a
Website: https://dlang.org
Category: system
Date: 2012-04-08
*/

/**
 * Known issues:
 *
 * - invalid hex string literals will be recognized as a double quoted strings
 *   but 'x' at the beginning of string will not be matched
 *
 * - delimited string literals are not checked for matching end delimiter
 *   (not possible to do with js regexp)
 *
 * - content of token string is colored as a string (i.e. no keyword coloring inside a token string)
 *   also, content of token string is not validated to contain only valid D tokens
 *
 * - special token sequence rule is not strictly following D grammar (anything following #line
 *   up to the end of line is matched as special token sequence)
 */

/** @type LanguageFn */
export default function(hljs) {
  /**
   * Language keywords
   *
   * @type {Object}
   */
  const D_KEYWORDS = {
    $pattern: hljs.UNDERSCORE_IDENT_RE,
    keyword:
      'abstract alias align asm assert auto body break byte case cast catch class '
      + 'const continue debug default delete deprecated do else enum export extern final '
      + 'finally for foreach foreach_reverse|10 goto if immutable import in inout int '
      + 'interface invariant is lazy macro mixin module new nothrow out override package '
      + 'pragma private protected public pure ref return scope shared static struct '
      + 'super switch synchronized template this throw try typedef typeid typeof union '
      + 'unittest version void volatile while with __FILE__ __LINE__ __gshared|10 '
      + '__thread __traits __DATE__ __EOF__ __TIME__ __TIMESTAMP__ __VENDOR__ __VERSION__',
    built_in:
      'bool cdouble cent cfloat char creal dchar delegate double dstring float function '
      + 'idouble ifloat ireal long real short string ubyte ucent uint ulong ushort wchar '
      + 'wstring',
    literal:
      'false null true'
  };

  /**
   * Number literal regexps
   *
   * @type {String}
   */
  const decimal_integer_re = '(0|[1-9][\\d_]*)';
  const decimal_integer_nosus_re = '(0|[1-9][\\d_]*|\\d[\\d_]*|[\\d_]+?\\d)';
  const binary_integer_re = '0[bB][01_]+';
  const hexadecimal_digits_re = '([\\da-fA-F][\\da-fA-F_]*|_[\\da-fA-F][\\da-fA-F_]*)';
  const hexadecimal_integer_re = '0[xX]' + hexadecimal_digits_re;

  const decimal_exponent_re = '([eE][+-]?' + decimal_integer_nosus_re + ')';
  const decimal_float_re = '(' + decimal_integer_nosus_re + '(\\.\\d*|' + decimal_exponent_re + ')|'
                + '\\d+\\.' + decimal_integer_nosus_re + '|'
                + '\\.' + decimal_integer_re + decimal_exponent_re + '?'
              + ')';
  const hexadecimal_float_re = '(0[xX]('
                  + hexadecimal_digits_re + '\\.' + hexadecimal_digits_re + '|'
                  + '\\.?' + hexadecimal_digits_re
                 + ')[pP][+-]?' + decimal_integer_nosus_re + ')';

  const integer_re = '('
      + decimal_integer_re + '|'
      + binary_integer_re + '|'
       + hexadecimal_integer_re
    + ')';

  const float_re = '('
      + hexadecimal_float_re + '|'
      + decimal_float_re
    + ')';

  /**
   * Escape sequence supported in D string and character literals
   *
   * @type {String}
   */
  const escape_sequence_re = '\\\\('
              + '[\'"\\?\\\\abfnrtv]|' // common escapes
              + 'u[\\dA-Fa-f]{4}|' // four hex digit unicode codepoint
              + '[0-7]{1,3}|' // one to three octal digit ascii char code
              + 'x[\\dA-Fa-f]{2}|' // two hex digit ascii char code
              + 'U[\\dA-Fa-f]{8}' // eight hex digit unicode codepoint
              + ')|'
              + '&[a-zA-Z\\d]{2,};'; // named character entity

  /**
   * D integer number literals
   *
   * @type {Object}
   */
  const D_INTEGER_MODE = {
    className: 'number',
    begin: '\\b' + integer_re + '(L|u|U|Lu|LU|uL|UL)?',
    relevance: 0
  };

  /**
   * [D_FLOAT_MODE description]
   * @type {Object}
   */
  const D_FLOAT_MODE = {
    className: 'number',
    begin: '\\b('
        + float_re + '([fF]|L|i|[fF]i|Li)?|'
        + integer_re + '(i|[fF]i|Li)'
      + ')',
    relevance: 0
  };

  /**
   * D character literal
   *
   * @type {Object}
   */
  const D_CHARACTER_MODE = {
    className: 'string',
    begin: '\'(' + escape_sequence_re + '|.)',
    end: '\'',
    illegal: '.'
  };

  /**
   * D string escape sequence
   *
   * @type {Object}
   */
  const D_ESCAPE_SEQUENCE = {
    begin: escape_sequence_re,
    relevance: 0
  };

  /**
   * D double quoted string literal
   *
   * @type {Object}
   */
  const D_STRING_MODE = {
    className: 'string',
    begin: '"',
    contains: [ D_ESCAPE_SEQUENCE ],
    end: '"[cwd]?'
  };

  /**
   * D wysiwyg and delimited string literals
   *
   * @type {Object}
   */
  const D_WYSIWYG_DELIMITED_STRING_MODE = {
    className: 'string',
    begin: '[rq]"',
    end: '"[cwd]?',
    relevance: 5
  };

  /**
   * D alternate wysiwyg string literal
   *
   * @type {Object}
   */
  const D_ALTERNATE_WYSIWYG_STRING_MODE = {
    className: 'string',
    begin: '`',
    end: '`[cwd]?'
  };

  /**
   * D hexadecimal string literal
   *
   * @type {Object}
   */
  const D_HEX_STRING_MODE = {
    className: 'string',
    begin: 'x"[\\da-fA-F\\s\\n\\r]*"[cwd]?',
    relevance: 10
  };

  /**
   * D delimited string literal
   *
   * @type {Object}
   */
  const D_TOKEN_STRING_MODE = {
    className: 'string',
    begin: 'q"\\{',
    end: '\\}"'
  };

  /**
   * Hashbang support
   *
   * @type {Object}
   */
  const D_HASHBANG_MODE = {
    className: 'meta',
    begin: '^#!',
    end: '$',
    relevance: 5
  };

  /**
   * D special token sequence
   *
   * @type {Object}
   */
  const D_SPECIAL_TOKEN_SEQUENCE_MODE = {
    className: 'meta',
    begin: '#(line)',
    end: '$',
    relevance: 5
  };

  /**
   * D attributes
   *
   * @type {Object}
   */
  const D_ATTRIBUTE_MODE = {
    className: 'keyword',
    begin: '@[a-zA-Z_][a-zA-Z_\\d]*'
  };

  /**
   * D nesting comment
   *
   * @type {Object}
   */
  const D_NESTING_COMMENT_MODE = hljs.COMMENT(
    '\\/\\+',
    '\\+\\/',
    {
      contains: [ 'self' ],
      relevance: 10
    }
  );

  return {
    name: 'D',
    keywords: D_KEYWORDS,
    contains: [
      hljs.C_LINE_COMMENT_MODE,
      hljs.C_BLOCK_COMMENT_MODE,
      D_NESTING_COMMENT_MODE,
      D_HEX_STRING_MODE,
      D_STRING_MODE,
      D_WYSIWYG_DELIMITED_STRING_MODE,
      D_ALTERNATE_WYSIWYG_STRING_MODE,
      D_TOKEN_STRING_MODE,
      D_FLOAT_MODE,
      D_INTEGER_MODE,
      D_CHARACTER_MODE,
      D_HASHBANG_MODE,
      D_SPECIAL_TOKEN_SEQUENCE_MODE,
      D_ATTRIBUTE_MODE
    ]
  };
}
